Although most countries abandoned the practice of forced fluoridation years ago, the debate is still a lively one here in America, where cities and states are still wondering whether to add the chemical to their water supplies. A bill being presented in New Jersey[2] would, if passed, mandate that all cities start using fluoride. The argument for fluoridation is ostensibly to prevent tooth decay, but Paul Connett and his coauthors say the science behind the practice is not sound, and that governments who pursue it are medicating their constituents by force.

Since the 1940s, municipalities across the United States have been voluntarily adding fluoride to their water supplies. Fluoride, as we all learned in elementary school, protects teeth against cavities. You’ll find it in toothpaste and in vitamin supplements. Children regularly get fluoride treatments at the dentist. We bathe in it, we eat it, and we drink it, knowingly or not, all of the time. This has been going on for nearly 70 years. Yet recently, it has become a source of contention for several communities across the country.

At the beginning of the year, Pinellas Countyin Florida halted water fluoridation for its nearly 700,000 residents. This, the result of a months-long campaign against what local tea-partiers saw as a Big Brother public health mandate. Pinellas County represents the largest population in the U.S. to halt the measure, but as TheNew York Timesreported[3] in October, “a growing number of communities are choosing to stop adding fluoride to their water systems.” The article cites 200 municipalities across the country that decided in recent years to forego the practice.

But why is politicized opposition to fluoride happening now?* The process has been in use since the 1940s, and the Centers for Disease Control and Prevention (CDC) hail it as one of the top preventative public health measures of all time. It is thoroughly supported[4] by the American Dental Association, and when it was initiated in the middle of the 20th century, rates of dental cavities fell by 50 percent or higher[5], arguably because of fluoride. But opposition groups, notably the Fluoride Action Network[6], a non-profit dedicated to fluoride-danger awareness, put forth a much darker picture. They say the effect of tap water fluoride on tooth decay is hard to pinpoint, and in a large enough quantity, fluoride is a toxin — one that can possibly make bones fragile, lower IQ in children, and contribute to bone cancer. They insist cavities can be prevented by brushing alone.

Like many environmental issues turned political, the two opposing sides in this debate present a dichotomous, confusing picture. What should residents in a community debating the practice believe? Ask the CDC whether fluoridation is worthwhile, and the answer is a resounding yes. Ask the Fluoride Action Network, and it is a fearful no. When it comes to environmental issues, misinformation runs rampant and so does emotion. At the intersection of politics and science, it’s often hard for the public to arrive at an objective truth. …

For just about every point the CDC makes in favor of fluoride, Paul Connett [a retired chemist and executive director of the Fluoride Action Network] has a counterpoint. For his full argument, read through his co-authored book, The Case Against Fluoride[1]. But here, his most pressing concerns:

Fluorides’ benefits are overstated. Connett says tooth decay rates in unfluoridated countries have decreased just as much as in the U.S. In addition, he points to other dental measures such as regular bushing and pit-and-fissure sealants that contribute to the decline in cavities.

Fluoride is a poison in high doses, which makes Connett worry about lifetime exposure. There are several studies from China which suggest that fluoride can affect IQ in developing children at levels of 2 ppm or greater. The NRC determined these studies to be methodologically flawed, but no researcher in the U.S. has pursued this topic.

Connett argues that the margin of safety of just a few parts per million is too small. “One of the things that makes this a very bad practice is that once you put fluoride in the water, you can’t control the dose,” he says. Someone who drinks two liters of water at 1 ppm is going to get as much fluoride as somebody drinking one liter of water at 2 ppm.

[1] The Case Against Fluoride: How Hazardous Waste Ended Up in Our Drinking Water and the Bad Science and Powerful Politics That Keep It There: http://www.chelseagreen.com/bookstore/item/the_case_against_fluoride:paperback

[2] A bill being presented in New Jersey: http://www.theatlantic.com/health/archive/2012/02/what-do-we-know-about-fluoride/252683/